A Circular Conformal Vivaldi Antenna Array with Suppressed Sidelobes

This paper investigates self-adapting conformal antennas for dynamic circular surfaces. Specifically, the radius of the circular surface, antenna element spacing, and needed phase compensation are all developed. A Vivaldi antenna with a -10dB$S_{11}$bandwidth from 4.3-9.8 GHz spanning the full IEEE C-band and a moderate gain of 5-9dBi was built for theoretical validation. Vivaldi antennas as radiators a $1\times 7$ circular conformal antenna array with a scanning capability of ±45° was created. Later, a modified Vivaldi antenna was designed to address the issue of high sidelobe level without compromising the S11 bandwidth offered by the Vivaldi antenna. A $1\times 7$ circular conformal modified Vivaldi antenna array was developed with a scanning capability of ±45° was created. Both case phase compensation is applied to each antenna element according to the beam-pointing direction. Overall there is good agreement in the theory and simulations of the designs.